A force limiting gear reducer for a lifting pinion of self-elevating platform, comprising a gear reducer divided in two parts, a first of said parts being directly connected to a pinion shaft and pinion support and a second said part comprising a shaft-mounted prime reducer with brake and motor connected...http://www.google.com.au/patents/US4480491?utm_source=gb-gplus-sharePatent US4480491 - Force limiting gear reducer for lifting pinion of self-elevating platform
